• Title/Summary/Keyword: Cold Temperature

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Preservatory Effect of Sweet Persimmons, Mandarin Oranges and Apples Stored in the Ear-Infrared Radiated Chamber (원적외선 방사체 시설내에 저장한 단감, 감귤 및 사과의 선도유지효과)

  • 정준호;조성환
    • Food Science and Preservation
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    • v.10 no.4
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    • pp.435-440
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    • 2003
  • Such fruits as nut persimmons, mandarin oranges and apples stored in the far-infrared radiated chamber at 5$^{\circ}C$ under 90% of relative humidity had been maintained in the fresh state for longer times than the control stored only in the cold chamber. Fruits stored in the far-infrared radiated chamber showed lower values in weight loss rate, microbial colony count and decay ratio and higher ascorbic acid content than the control stored only in the told room through the storage period. We confirmed that fruits stored in the far-infrared radiated chamber under low temperature and high humidity showed least changes in quality properties through the storage period and the far-infrared radiated facilities could be a good storage system.

Studies on the Regional Distribution and Some Ecological Characteristics of Chinese White-wax Scale in Korea (국내에서 서식하는 쥐똥밀깍지벌레(Ericerus pela)의 분포 및 생태에 관한 연구)

  • 박인규;마영일;윤형주;양성열
    • Korean journal of applied entomology
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    • v.37 no.2
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    • pp.137-142
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    • 1998
  • The regional distribution and some ecological characteristics of Chinese white-wax scale, Ericerus pela Chavannes, were investigated from 1996 to 1997. It was found that 10.8% of the stems of the privet, Ligustrum obtusifolium infested with the scale in Chtingpyijng, whereas only 1.1% of them infested in Y6ngwol and Pyongtaek. The average survival rate of the female adult marked 85.3% after it hibernated on the privet, Ligustrum obtusifolium. A female laid 7,783.5 eggs in average and 36.7% of females fell on the range of 7,000-10,000 eggs. It sized 0.40 mm in length and 0.21 mm in width. The hatchability was highest at 27$^{\circ}$C with 66.8% and it seemed the optimum temperature for incubation. The pupation rate was lower than 50.0% at the above experimental temperatures and the emergence rate marked 67.3% at 25$^{\circ}$C. When the egg was preserved at the various low temperatures, it was found that the egg could be preserved at lS$^{\circ}$C for 50 days in maximum.

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Microbiological and Sensory Characteristics of Electron Beam Irradiated Squid Jeotkal and Its Ingredients (전자선 조사 양념 오징어 젓갈 및 부재료의 미생물학적 및 관능적 특성)

  • Kim, Bin-Na;Jung, Samooel;Choe, Jun-Ho;Liu, Xian De;Jo, Cheo-Run
    • Korean Journal of Agricultural Science
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    • v.35 no.2
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    • pp.155-165
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    • 2008
  • A seasoned squid Jeotkal, Korean traditional fermented seafood, and its ingredients for manufacturing, including red hot pepper powder, ground garlic, sesame seeds, were irradiated with 0, 0.5, 1, 2, and 5 kGy by electron beam and stored at $4^{\circ}C$ for 4 weeks to determine the changes in microbiological and sensory characteristics. The initial contamination of squid Jeotkal such as total aerobic bacteria, yeast & mold, and coliform bacteria were at the levels of 2.88, 3.04, and 4.20 log CFU/g, respectively. However, electron beam irradiation with does at 5 kGy reduced the total aerobic bacteria to about 1 log CFU/g. Yeast & mold and coliform bacteria were reduced to 1-2 log CFU/g after 2 kGy of irradiation and reached to undetected level when the sample was irradiated at 5 kGy and following storage at $4^{\circ}C$ for 4 weeks. Sensory characteristics showed that electron beam irradiation of up to 5 kGy did not adversely affect overall acceptability of squid Jeotkal and its ingredients during cold storage. Therefore, electron beam irradiation is one of the possible means to improve storage stability of seasoned squid jeotkal, which has limited alternative sterilization methods due to the temperature characteristics of the products.

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Effect of Water Temperature and Packing Type on Quality of Fresh-cut Pak-choi (세척 청경채의 선도 유지에 대한 세척수 온도와 포장 형태의 영향)

  • Kim, Byeong-Sam;Chang, Min-Sun;Park, Shin-Young;Cha, Hwan-Soo;Kwon, Ki-Hyun;Kim, Gun-Hee
    • Food Science and Preservation
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    • v.15 no.1
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    • pp.1-8
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    • 2008
  • Quality attributes of fresh-cut pak-choi (Brassica campestris var. chinensis) as affected by hydrocooling and packing were investigated in terms of weight loss, respiration, vitamin C content, total chlorophyll content, microbial load and sensory properties during storage at 4 and $10^{\circ}C$. Fresh pak-choi was trimmed and washed with cold water $(1^{\circ}C)$ as well as tap water $(6^{\circ}C)$ for 30 sec 3 times and then packaged in PP (polypropylene) film bag and PETE (polyethylene terephthalate) bay, and stored for 9 days at 4 and $10^{\circ}C$. Weight loss was decreased by washing and packing generally. Respiration rate was increased slowly over the storage at $4^{\circ}C$. Vitamin C content and total chlorophyll contents of pak-choi packaged within PETE bay decreased gradually during storage. Hydrocooling and packing within PETE bay treatments resulted in approximately 1-2 log CFU/g reduction of microbial load.

The perception of girls' middle & high school students in Seoul on the usage of trousers as school uniform (서울시 여자 중.고등학교 학생의 바지교복에 대한 착용실태 및 인식)

  • Kim, Sung-Sil;Shin, Hye-Won
    • Journal of Korean Home Economics Education Association
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    • v.22 no.1
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    • pp.137-148
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    • 2010
  • The usage status of trousers as school uniform for girl's middle and high school students in Seoul and the perception on trousers as school uniform were analyzed. Students who wore 'skirts only' were the greatest and students who wore 'trousers only' were higher in the case of winter uniform than in summer uniform. The most popular reason to wear skirts was 'because most of their fellow students wore skirts' in both winter and summer. The main reason for wearing trousers was 'because it was easy to cope with changes in temperature' in winter and 'because it allowed more comfortable movements' in summer. Students who wore trousers were generally satisfied with wearing trousers as school uniforms. However, they showed a low degree of satisfaction about design and color of trousers. The students preferred slim and straight trousers, and black col or with beige and blue being the next color. Students in general had low level of recognition for the need to wear trousers. Students perceived trousers as being cold-proof and comfortable for physical activities. But they also perceived that trousers were not suitable for improving their appearances and expressing their characteristics. Especially, the students who wore trousers tended to think that trousers reduced their cares for their personal attire and that trousers were good for wearing after school, but the students who did not wear trousers were found to think contrary.

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A Study of the Holocene Climate Change Using Humus Analysis of the Nam River Basin in Jinju, Southern Part of Korea (휴무스분석을 통한 진주 남강유역의 홀로세 기후 변화 연구)

  • Jung, Heakyung;Kim, Cheong Bin
    • Journal of the Korean earth science society
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    • v.33 no.6
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    • pp.510-518
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    • 2012
  • The Holocene climate change has been studied based on humus analysis of sediments that came from the Nam River basin in the Jinju, Gyeongnam. Humus and soil organic carbon analyses were performed to interpret the climate change and OSL dating and radiocarbon dating were conducted to determine the age of the sediments. The age determinations revealed that the sediments were formed approximately from $10,000{\pm}100$ yr. BP to $4,370{\pm}50$ yr. BP (2,970 BC) The deposits were classified into five layers based on sediments color and texture, and the climate change of each layer has been interpreted. The general climate was found out to be warm. The study result illustrated that section I was the lowest layer and section V the highest among the five surveyed sections. One the other hand, relatively cold events were detected in the sections ranging from I and II to III in terms of temperature. In term of humidity, sections II and III are estimated to have been relatively dry. Sections IV and V were relatively warm and dry, and the section IV tends to be warmest of the entire sedimentary. In addition, there is a tendency that the total soil organic carbon shows relatively high values under the cooler and humid climatic condition.

An Experimental Study on the Effect of Reduced Slag and Gypsum on Concrete at Low Temperature(-5℃) (저온(-5℃)에서의 환원슬래그 및 석고가 콘크리트에 미치는 영향에 관한 실험적 연구)

  • Kim, Hyeong-Cheol;Choi, Hyun-Kuk;Min, Tae-Beom;An, Dong-Hee;Choi, Si-Hyun;Lee, Han-Seung
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.3
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    • pp.279-285
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    • 2017
  • In this study, the development of concrete preventing initial frost damage and durability about that were evaluated by using anti-aging agent and admixture(reduced slag). As a result of experiment, initial hydration heat was increased by $C_{12}A_7$ of reduced slag components but it was not effective to development of strength. Also fluidity decreased with increasing replacement of reduced slag. This suggested that fluidity was low by rapid setting due to absent of gypsum in reduced slag components. In case of CR2G specimen that added 4% gypsum, the flow ability was higher than plain. It is considered that concrete developed using reduced slag should use $SO_3$. Result of durability experiments, the durability decreased with increasing replacement amount of reduced slag.

Development of Concrete Quality Inspection and Document Management System Using Mobile and Web Technologies (모바일 기술 및 웹을 활용한 콘크리트 품질시험 및 문서관리 시스템 개발)

  • Kim, Young-Suk;Lee, Jae-Kwon;Jung, Un-Suk
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.4
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    • pp.193-205
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    • 2008
  • Quality is an important keyword representing the corporate competitiveness and image in today' s construction industry. Especially in concrete construction, any problems or defects in fresh concrete can significantly degrade the entire quality and performance of the facility built. Thus, adequate quality inspection and testing must be exercised over the fresh concrete, if concrete with the required strength, durability and appearance is to be obtained. The testing of concrete delivered to the construction job site involves testing of fresh concrete and performing strength tests on hardened concrete. The principal tests conducted on fresh concrete include the slump test and tests for air and salt content. The temperature of fresh concrete should be checked out hot or cold weather concreting. The 7-day and 28-day strength of hardened concrete are also determined by compression tests on usually cylinder samples. However, it is very complex and time-consuming process requiring a lot of efforts to document those on-site concrete testing results and to accumulate their historical data. The primary objective of this study is to suggest a unique PDA and web-based system which enables an on-site quality manager to effectively conduct the concrete inspection and testing, automatically document and accumulate the collected historical data, and promptly obtain the approval from supervisors. Finally, it is anticipated that the effective use of the proposed PDA and web-based system would be able to improve reliability of the concrete quality inspection and testing data as well as significantly reduce the approval process.

Physicochemical Properties and Antioxidant Activity of Extruded Rice Flour with Various Cacao (Theobroma cacao L.) Bean Content (카카오 빈 함량에 따른 쌀 압출성형물의 이화학적 특성 및 항산화 활성)

  • Park, Ju-Yeon;Kim, Young-Ho;Ryu, Gi-Hyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.11
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    • pp.1327-1335
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    • 2017
  • This study was carried out to determine the effect of cacao bean addition on the physicochemical properties of extruded rice flour. Rice-based cacao beans (0, 20, 40, 60%) were extruded at a die temperature of $130^{\circ}C$, screw speed of 200 rpm, and moisture content of 25%. As the content of cacao beans increased from 20% to 60%, expansion index decreased, while piece density and specific length increased. The water soluble index and water absorption index of the extrudate increased through extrusion cooking. Lightness decreased as cacao bean content increased while redness increased. As the content of cacao beans increased, paste viscosity decreased. Cold peak viscosity was observed in all extrudates of raw roasted cacao beans. ${\alpha},{\alpha}$-Diphenyl-${\beta}$-picrylhydrazyl (DPPH) radical-scavenging activity increased upon extrusion and cacao bean addition. As content of cacao beans increased, non-roasted cacao beans had higher total phenolic contents than roasted cacao beans. This study showed that addition of cacao beans to extruded rice snack improved antioxidant activity.

Distribution of Water Masses and Distribution Characteristics of Dissolved Inorganic and Organic Nutrients in the Southern Part of the East Sea of Korea: Focus on the Observed Data in September, 2011 (동해 남부 해역의 수괴 분포와 용존 무기 및 유기 영양염의 분포 특성: 2011년 9월 관측자료를 중심으로)

  • Kwon, Hyeong Kyu;Oh, Seok Jin;Park, Mi Ok;Yang, Han-Soeb
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.17 no.2
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    • pp.90-103
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    • 2014
  • Distribution characteristics of water masses, dissolved inorganic and organic nutrients were investigated in the southern part of the East Sea of Korea in September, 2011. On the basis of the vertical profiles of temperature, salinity and dissolved oxygen, water masses in the study area were divided into 4 major groups, such as WM (water mass)-I, WM-II, WM-III, WM-IV. Their characteristics were similar to Tsushima Surface Water (TSW), Tsushima Middle Water (TMW), North Korea Cold Water (NKCW) and East Sea Proper Water (ESPW), respectively. In the vertical profiles of dissolved nutrients, dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) concentrations were highest in the WM-IV, followed by WM-III, WM-II, WM-I. On the contrary, distribution of dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) were highest in the WM-I, followed by WM-II, WM-III, WM-IV. Although the DIN : DIP ratio in all of the water masses was similar to Redfield ratio(16), the DIN : DIP ratio in mixed layer was about 5.3, indicating that inorganic nitrogen is the limiting factor for the growth of phytoplankton. However, the DON proportion in dissolved total nitrogen (DTN) was about 70% in the mixed layer where inorganic nitrogen is limiting factor. Thus, enriched DON may play an important source of the nutrient for the growth of phytoplankon in the East Sea.